"The Federation. I know it well from the Defiant's files. There's a reason they're classified. Equality. Freedom. Co-operation. Cornerstones for successful cultures. Delusions that Terrans shed millennia ago. Destructive ideals that fuel rebellions and I will not let you infect us again."

The rebellion appeared to have little information about her except that the emperor was ruthless. Her identity was not made public, being known as the faceless emperor. (DISepisodes: "Despite Yourself", "The Wolf Inside")

In spite of the Empire’s xenophobic tendencies, Emperor Georgiou had taken titles native to the Vulcan, Klingon, and Andorian subjects of her Empire, as she was addressed as "Overlord of Vulcan, Dominus of Qo'noS," and "Regina Andor", among others, symbolic of her success at conquering and oppressing other species.

The Emperor, learning of Lorca's betrayal, sent Captain Burnham after Lorca, who by then was in command of the ISS Buran. Both Lorca and Burnham ended up missing, presumed dead, and the ISS Buran was destroyed. (DISepisode: "The Wolf Inside")

Georgiou faced her former adopted family-turned-traitors when Michael Burnham of the primary universe stranded in the mirror universe, and traveled to meet Georgiou on the ISS Charon. Burnham pretended to be her counterpart until Georgiou was about to execute her. In a subsequent negotiation to have the emperor assist Burnham's ship, the USS Discovery, to return to its native universe, both women realised that Burnham's Lorca was indeed the escaped traitor from the mirror universe. (DISepisode: "Vaulting Ambition")

Lorca then initiated a rebellion against Georgiou, quickly escaping from his confinement and rallying his comrades who had been condemned to the Charon's agony booths. They quickly took the ship with the assistance of the mirror Paul Stamets, who had helped them in their first coup attempt, only to sell out to Georgiou. During a confrontation in which most of the crew still loyal to her were killed, she performed an emergency site-to-site transport, hiding in her personal quarters and wearing a special bracelet that made her undetectable to the ship's sensors. Lorca then took control of the Charon and threatened to destroy the USS Discovery.

Burnham found Georgiou and proposed a plan, to exploit Lorca's desire to put her by his side once more. They pretended to surrender in exchange for letting Discovery go. When the Discovery came out of warp, Lorca was distracted by Saru and Burnham's conversation, giving her time to subdue the guards around her and Georgiou. The fight turned in their favor quickly, and when Burnham released Lorca from gunpoint, citing the Starfleet ethos, Georgiou executed him with a sword through the chest for his treason. He was then unceremoniously kicked through the "sunroof" into the mycelial reactor and his end. Georgiou finally warmed up to Burnham, saying that for one second, she was her daughter again, and volunteered to stay behind and give her enough time to escape as Lorca's forces surrounded them. Instead, as the transporter beam energized, Burnham unexpectedly lunged at her and took Georgiou with her to Discovery before the Charon was destroyed, along with all of Lorca's men. (DISepisode: "What's Past Is Prologue")

With Georgiou and Burnham aboard, the Discovery engaged its spore drive and crossed back into the primary universe, having overshot their arrival time by nine months.

Saru was initially shocked at seeing Georgiou alive, believing her to be his former captain. She quickly corrected him and immediately demanded that he kneel as a slave. Burnham revealed that indeed this Kelpien was her captain. However, Georgiou was quick to remind Burham that they had previously dined on entrails of his brethen.

Over nine months, the Federation war with the Klingons had taken its toll, with Starfleet losing one third of its fleet and over twenty percent of its territory occupied. Losses were so great, Admiral Katrina Cornwell and Ambassador Sarek wished all knowledge of Discovery's journey to the alternate universe be buried and locked down.

On meeting with Georgiou, Cornwell and Sarek found her resemblance to Captain Phillipa Georgiou to be remarkable. With Burham's assurance that Georgiou's appearance in their universe was without motive, Cornwell admitted it remained complicated. Georgiou wished to return to the mirror universe. Burnham stated that she had escaped a violent revolution and should be granted political asylum within the Federation. Georgiou was to be held at Starbase I, until Starfleet Command determined a proper course of action, this changed when the Discovery learned that the starbase had been occupied by Klingons.

Georgiou's rule of the Terran Empire extended throughout every system in their galaxy, conquering places Starfleet hasn't dared to explore. Burnham wanted to know how Georgiou had defeated the Klingon Empire. Georgiou explained that the Klingons were like cancer cells, constantly dividing and the way to root them out was to destroy them at the source, Qo'noS.

As the Klingons were preparing to strike Sol system, the core system of the Federation, the response was to take the fight to Qo'noS. A coordinated attack against their planetary defense batteries, followed by the destruction of all military targets planet-wide. A single offensive so destructive, it would cause the Klingons to retreat back to their homeworld.

Georgiou provided Burnham with intelligence that Qo'noS is essentially a planet of caves, some large enough to house a Crossfield-class starship. The Discovery could use its spore drive to enter one of these caves and map the terrain from the inside-out, reducing the risk of detection.

Meeting with Sarek in private, Georgiou offered her help in winning the war. While she had provided Burnham with the intelligence she could handle, the Qo'noS of her universe was little more than a blackened mass of dust. Burnham's plan would prove effective, but only temporarily. Georgiou offered to bring the Klingons to their knees once and for all. If she got her freedom, she would assure victory for the Federation.

Sarek negotiated with the Federation Council and received approval of Georgiou's plan and that they had no choice but to proceed.

Georgiou took the role of Captain Phillipa Georgiou to chart the Discovery's course to Qo'noS. To cover up her alternate universe origin, Cornwell claimed that although presumed long-dead, she was rescued in a highly classified raid of a Klingon prison vessel. The mission was perilous expedition and Starfleet was confident she was uniquely qualified to get the Discovery there and do what needs to be done. (DISepisode: "The War Without, The War Within")

The war concluded when Georgiou planted a nuclear device within a volcano on Qo'noS. Preventing Georgiou from detonating the device, Burnham gave the detonator to L'Rell, who used the threat of detonating the device to force the leaders of the Great Houses to accept her leadership and ordered Klingon forces to halt their advance on the Federation. (DISepisode: "Will You Take My Hand?")